Polyacrylate- based conductive coatings were prepared from polyacrylate emulsion as matrix andcarbon black (CB) whose surface was treated with titanate coupling agent as conducting particles. One kind oforganic crystal was added to study its effects on the electrical conductivity and PTC ( positive temperature coeffi-cient ) effect of the conductive coatings. Experimental results show that the coatings containing only polyacrylateemulsion and CB exhibit an excellent electrical conductivity but bad PTC effect, and when organic crystal is added,PTC effect is characterized and can increase by 2 orders of magtitude. The critical transformation temperature ofpolyacrylate emulsion/CB PTC composites is decided by melting point of organic crystals.